i am working on my cai and i have both 3" and 2.5" piping. the intake is going to run down to where my fog light is (fogs taken out). Would is be best to go with 3" because of the amount of bends to get the filter down there or should i use 2.5?

 

I have an AEM and I believe that it is 2.5". The fit near the battery is very tight. If you are going to use 3" piping, you will need to move your battery.

 

thanks for the input

 

Don't forget my man, the bigger the intake, the lower the air velocity.

 

thanks redz. i should be able to have it all welded buy the middle of next week. i'll post some pics

 

Hi guys, I don't mean to contradict any about the intake piping, but I have always heard 3" is just too much for the Tib. I have right now installed on my RD Tib a 3" CAI (custom made) and I don't feel I lost torque on low rpm's and I feel I gain pretty much on medium (3500 and upper rpm).

Well, my Tib is MAP based, and there is my point, I think maybe 3" it's not too much, but maybe it's because of your MAF size (2,5") that using a bigger CAI piping is worse that sticking to the MAF size (a change in piping size can create flow distorsions that are worse than a smaller pipe).

Well, just wanted to throw in my 2c. Maybe if there was a bigger MAF, a bigger intake would work?

Also I have a intalled the 1.8 Cam, and a 2,5" catback exhaust, so maybe that's also why I don't feel any lack of torque on the lower part of the tach.

 

3 inch is too big for MAF, not for MAP.

Very good point.

 

A good rule of thumb is to go 25% larger than the diameter of your throttlebody. Like Redz said, the larger the intake the slower the air velocity, this means that you may get more hp out of it, bit it's all going to be high end, where the velocity is sped up because of the engine. Also, you want to taper it down as it reaches the TB so that the air speed can increase and you get more air into the engine.

 

<div class='quotetop'>QUOTE (supry)</div><div class='quotemain'>A good rule of thumb is to go 25% larger than the diameter of your throttlebody. Like Redz said, the larger the intake the slower the air velocity, this means that you may get more hp out of it, bit it's all going to be high end, where the velocity is sped up because of the engine. Also, you want to taper it down as it reaches the TB so that the air speed can increase and you get more air into the engine.</div>

what about 3" up to the MAF then 2.5 to the TB. i was planning on keeping the stock intake tube from the TB to the MAF. Would that be tapered enough or should i just switch the stock tube while im at it?

 

That should work decent since its just the elbow after the maf, I'm not that certain, but I think that the elbow is smaller down by the maf than up by the TB, but I haven't looked under my hood in a while, if it isn't you should be all set.